Role of thymidine phosphorylase and dihydropyrimidine dehydrogenase in tumour progression and sensitivity to doxifluridine in gastric cancer patients

This study was designed to investigate the role of thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) on tumour progression and sensitivity to 5'-deoxy-5-fluorouridine (5'-DFUR). Tumour tissue was obtained from surgically resected samples from 93 patients with primary gastric cancer. Tumour TP and DPD expression levels were determined by the enzyme-linked immunosorbent assay (ELISA) system and compared with several clinicopathological factors and in vitro sensitivity to 5'-DFUR. DPD showed no correlation with any clinicopathological factors. However, the TP level was significantly correlated with the depth of tumour, lymphatic invasion and venous invasion. In comparison with 5'-DFUR sensitivity, there was a weak inverse correlation between the DPD level and the sensitivity to 5'-DFUR (r(s)=-0.361). Furthermore, the TP/DPD ratio showed a significant correlation with 5'-DFUR sensitivity (r(s)=0.634). In a subgroup of patients with postoperative 5'-DFUR administration, the survival rate was significantly better in patients with a high TP/DPD ratio (n=8) than in those with low TP/DPD ratio (n=14) (P=0.0140). These results suggest that sensitivity to 5'-DFUR is predictable by measurement of both TP and DPD levels.

Modulation of heat-induced cell death in PC-3 prostate cancer cells by the antioxidant inhibitor diethyldithiocarbamate

OBJECTIVE

To examine the relationships between the form of cell death (apoptosis or necrosis), reactive oxygen species (ROS) generation, superoxide dismutase (SOD) activity and the level of heat-shock protein 70 (hsp 70) expression after thermotherapy of PC-3 prostate cancer cells; also assessed were the tumoricidal effects of combined treatment with both heat and the antioxidant inhibitor diethyldithiocarbamate (DDC).

MATERIALS AND METHODS

PC-3 cells were treated with thermotherapy at 42, 43 or 44 degrees C for 30, 60, 90 or 120 min. Cell proliferation, ROS generation, SOD activity and cellular hsp 70 level were determined using tetrazolium-based cytotoxicity, fluorescent dichlorofluorescein (DCF) and nitroblue tetrazolium assays, Western blot analysis and flow cytometry, respectively. The apoptotic and necrotic cells were determined by staining with propidium iodide and fluorescein isothiocyanate-labelled annexin V. These variable were also measured after combined treatment of PC-3 cells with 1 mmol/L DDC and thermotherapy at 43 or 44 degrees C for 60 min.

RESULTS

Cell survival was significantly lower after heating cells at 43 degrees C for 60, 90 and 120 min and at 44 degrees C for all periods tested (P<0.05). At 43 degrees C apoptosis increased with the duration of heating and was similarly enhanced after heating at 44 degrees C for 30 min. Necrosis was not increased by heating at 42 or 43 degrees C, but was markedly enhanced after heating at 44 degrees C with both the duration of heating and with time after heating. Significant increases in DCF production were induced by heating at 43 degrees C for 60, 90 and 120 min (P<0.05) and at 44 degrees C at all times (P<0.010-0.005). There was a significant correlation between the level of ROS generation and necrosis (P<0.001) but no correlation between the ROS level and apoptosis. SOD activity increased in cells after heating at 43 degrees C, with significant differences among cells heated for 60, 90 and 120 min (P<0.05). After heating at 44 degrees C, SOD activity was maximal in cells heated for 30 min (P<0.005), by 30 min and then decreased with time after heating. There were significant increases in hsp 70 level in cells heated at 43 degrees C for 90 and 120 min (P<0.05) and at 44 degrees C for 30 and 60 min (P<0.05 and <0.025, respectively). Hsp 70 levels decreased after heating at 44 degrees C for 90 and 120 min. The combination of DDC and heating significantly increased ROS generation and the percentage of cell death, and decreased SOD activity (P<0.05).

CONCLUSION

These findings show a qualitative change in the form of cell death induced by thermotherapy of PC-3 cells, which changed from apoptosis to necrosis according to the degree and duration of heating. Mild thermotherapy induced marginally low occurrence of apoptosis of PC-3 cells and DDC may represent a useful future strategy for the treatment of prostate carcinoma.

Roles of thymidylate synthase and dihydropyrimidine dehydrogenase in tumor progression and sensitivity to 5-fluorouracil in human gastric cancer

BACKGROUND

The role of thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) enzyme activities in tumor progression and sensitivity to 5-fluorouracil (5-FU) were evaluated.

MATERIALS AND METHODS

TS and DPD activities were measured in 81 clinical samples of gastric cancer. TS and DPD activities were determined by 5-fluorodeoxyuridine monophosphate binding assay and by radioenzymatic assay, respectively. Sensitivity to 5-FU was determined by in vitro ATP assay.

RESULTS

There was no correlation between TS activity and sensitivity to 5-FU. However, a weak correlation was found between DPD activity and sensitivity to 5-FU. In a subgroup of patients who did not receive adjuvant chemotherapy, overall survival was poorer in patients with high TS activity (p=0.0265). Conversely, in a subgroup of patients who received 5-FU-based adjuvant chemotherapy, overall survival was poorer in patients with high DPD activity (p=0.0465).

CONCLUSION

These results suggest that TS has an important role in tumor progression and DPD may be the dominant predictor of 5-FU sensitivity in gastric cancer.

Alterations of beta- and gamma-catenin in N-butyl-N-(-4-hydroxybutyl)nitrosamine-induced murine bladder cancer

Abnormal degradation of beta-catenin caused by alteration of the glycogen synthase kinase-3beta (GSK-3beta) consensus motif is an important step for carcinogenesis. We hypothesize that beta- and gamma-catenin may play an important role in the pathogenesis of bladder cancer. We tested this hypothesis through analysis of beta- and gamma-catenin in both murine and human bladder cancers. A murine bladder cancer model was prepared by use of N-butyl-N-(-4-hydroxybutyl)nitrosamine (BBN) in 6-week-old male B6D2F1 mice. After 4, 8, 12, 16, 20, 24, and 28 weeks of BBN treatment, bladder specimens were harvested and analyzed for both protein and gene expression for beta- and gamma-catenin. Mutational analysis of the NH(2)-terminal regulatory domains of beta- and gamma-catenin was performed in each specimen by PCR-single-strand conformational polymorphism (SSCP) analysis. Mutations were further confirmed by direct DNA sequencing with a dye terminator method. Human bladder cancer specimens with normal tissues, dysplasia, carcinoma in situ, and carcinoma of grades, 1, 2, and 3 were also analyzed for beta- and gamma-catenin expression. beta- and gamma-catenin were analyzed for mutations by SSCP and direct DNA sequencing. Intracellular accumulation of beta- and gamma-catenin was observed in 6 of 20 invasive carcinoma specimens. There was no intracellular accumulation of beta- and gamma-catenin in mucosal dysplasia, papillary or nodular dysplasia, and carcinoma in situ specimens. On an SSCP analysis for beta-catenin, abnormal bandshifts were detected in two invasive carcinomas with intracellular beta-catenin accumulation. Further sequencing revealed two mutations [AGT(S) to ATT(I) and TCT(S) to CCT(P)] within the consensus motif for GSK-3beta phosphorylation. On the other hand, SSCP analysis for gamma-catenin followed by sequencing revealed three mutations in two invasive carcinomas with intracellular accumulation of gamma-catenin. These three alterations affected the 3' downstream region outside the GSK-3beta phosphorylation site [ACC(T) to GCC(A), CTC(L) to ATC(I), and CTC(L) to ATG(M)]. In human bladder cancer, beta- and gamma-catenin expression was significantly weaker than in normal bladder. On SSCP analysis one abnormal bandshift was observed in high-grade human bladder cancer with intracellular beta-catenin accumulation. DNA sequencing revealed mutation TCT(S) to TGT(C). In summary, alterations in beta- and gamma-catenin are late events favoring tumor progression in mouse BBN-induced bladder cancer. Changes affecting the GSK-3beta phosphorylation site appear to be associated with activation of beta-catenin, but not with activation of gamma-catenin. In human blabber cancer, beta- and gamma-catenin expression is similar to the expression in the mouse model. The present study demonstrates that beta- and gamma-catenin may play an important role in bladder cancer progression.

[Novel biodegradable materials for drug delivery systems (DDS)]

The authors provide three new and different types of fibrin gels (FCs) and a chitosan sheet (BC) using an ultraviolet (UV)-crosslinking method. They are 1) FC-UV, 2) gelatin entrapped FC; FC (Gp)-UV, 3) chitosan entrapped FC; FC (Cs)-UV and 4) BC-UV. Each material was loaded with aqueous cis-platinum (CDDP), and both the degradation of the drug carriers and the release profile of the CDDP were examined in vitro. The FCs, 1)-3), gradually degraded and dissolved within 10-12 days. The BC, 4), maintained its original weight for more than 30 days. Each FC showed a sustained release of CDDP for 10 days, while BC provided an initial bursting of the loaded drug. New materials 2) and 3) show great potential as drug carriers for DDS and further in vivo studies are now proceeding.

Arginine-specific ADP-ribosyltransferase on the surface of gizzard smooth muscle cells and the involvement of phosphatidylinositol 3-kinase in maintaining the activity of this transferase

An arginine-specific ADP-ribosyltransferase activity was detected in chicken gizzard smooth muscle, and the specific activity is highest in the membrane fraction. This transferase is released from the membrane fraction by phosphatidylinositol-specific phospholipase C (PI-PLC), suggesting that it is a glycosylphosphatidylinositol (GPI)-anchored protein. When primary cultured gizzard smooth muscle cells (SMCs) were incubated with [adenylate-(32)P]NAD, several proteins were labeled. The labeling was inhibited by preincubation of the cells with PI-PLC, or by the addition of L-arginine to the reaction, and was sensitive to hydroxylamine treatment. The activity of the transferase was maintained in differentiated SMCs cultured with insulin, but was dramatically decreased concomitantly with cell dedifferentiation induced by serum or a specific PI3-kinase inhibitor, LY294002. These results indicate that the GPI-anchored arginine-specific ADP-ribosyltransferase is expressed on the surface of differentiated SMCs and can modify several cell surface proteins. Our results also suggest that PI3-kinase is involved in the regulation of transferase activity during differentiation.

Improved reproducibility of intravascular ultrasound assessment of coronary in-stent neointima with the use of an echogenic contrast agent

The present study evaluated a new technique that has the potential to improve the border detection of in-stent neointima using an echogenic contrast agent during intravascular ultrasound (IVUS). To confirm the reproducibility of IVUS imaging for measuring the cross-sectional in-stent neointima area, inter- and intra-observer variability and correlation were determined. Conventional IVUS (plain IVUS) and IVUS using a contrast agent (contrast IVUS) were performed in 24 subjects 6.5+/-1.5 months after undergoing a Palmaz-Schatz coronary stent implant. Conventional IVUS delineated completely the in-stent neointima in 6 subjects (25%). In the remaining 18 subjects (75%), delineation of the neointima was incomplete despite the use of various combinations of imaging conditions (eg, transmission, compress, post-process). With contrast IVUS, the boundary of the neointima, and therefore the neointima area, was clearly distinguishable, and this resulted in complete delineation of the neointima in all 24 subjects. With a contrast agent, inter- and intra-observer variability significantly decreased (0.94+/-0.69mm2 conventional IVUS vs 0.37+/-0.40mm2 contrast IVUS, p<0.001; 0.69+/-0.56mm2 conventional IVUS vs 0.07+/-0.10mm2 contrast IVUS, p<0.0001; respectively). Thus, contrast IVUS provides a reproducible method for the quantitative analysis of in-stent neointima with excellent inter- and intra-observer correlation.

Percutaneous ulnar artery approach for coronary angiography: a preliminary report in nine patients

The radial artery approach is becoming more popular for diagnostic cardiac catheterization and interventional procedures because of its lower incidence of access site complications and decreased patient discomfort after the procedure. However, Allen's test reveals inadequate blood supply through the ulnar artery to the hand, and therefore the approach does not seem to be suitable in 10%-30% of patients. Here we demonstrated a new percutaneous ulnar artery approach for coronary angiography in nine patients. We succeeded in obtaining an entry site into the left ulnar artery in seven patients. The average time for cannulation and that for catheterization procedure were comparable with those of the radial approach previously reported from other laboratories. Complications such as bleeding, loss of an ulnar pulse, ulnar nerve injury, and the formation of an aneurysm or fistula were not observed in any patient. The ulnar approach may be another technique that decreases patient discomfort and risk, while preserving the radial artery as a potential coronary bypass graft for surgical myocardial revascularization. Cathet Cardiovasc Intervent 2001;53:410-414.

Nitric oxide regulates actin reorganization through cGMP and Ca(2+)/calmodulin in RAW 264.7 cells

Nitric oxide (NO) has been reported to be involved in the regulation of pseudopodia formation, phagocytosis and adhesion in macrophages through the reorganization of actin. In the present study, we directly separated the globular (G) and filamentous (F) actin from quiescent or NO-stimulated macrophage-like cell line RAW 264.7 cells in order to investigate the dynamic redistribution of actin pools. We also focused on the regulatory mechanisms of actin assembly, induced by NO and its possible subsequent signaling pathway. We showed that predominant G-actin coexisted with Triton X-100-insoluble filamentous (TIF) and Triton X-100-soluble filamentous actin in resting RAW 264.7 cells. The exogenous NO produced by (+/-)-(E)-2-[(E)-hydroxyimino]-6-methoxy-4-methyl-5-nitro-3-hexenamide (NOR1), the endogenous NO induced by lipopolysaccharide (LPS) plus interferon-gamma (IFNgamma), and dibutyryl-cGMP increased the contents of TIF-actin in dose- and time-dependent manners and altered its morphology. The increase in the TIF-actin contents induced by NOR1 or LPS plus IFNgamma was efficiently blocked by the radical scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide and the soluble guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one or the arginine analogue N(G)-monomethyl-L-arginine acetate, respectively. Preincubation with the calmodulin antagonist W-7 almost completely blocked the NO-induced TIF-actin increase and morphological change. On the other hand, preincubation with C3 transferase, an inhibitor of Rho protein, efficiently prevented the change in cell morphology, but had no effect on the TIF-actin increase. We postulate that cGMP and subsequent Ca(2+)/calmodulin may be key regulators of actin reorganization in NO-stimulated RAW 264.7 cells.

Utilization of an alternative carbon source for efficient production of human alpha(1)-antitrypsin by genetically engineered rice cell culture

Human alpha(1)-antitrypsin was produced by genetically engineered rice cells using promoter and signal peptide of a rice alpha-amylase isozyme. Batch and continuous cultures were employed to investigate the effects of alternative carbon sources on the alpha(1)-antitrypsin production. While this expression system is inducible by sugar depletion, we have found that the productivity of alpha(1)-antitrypsin increased 2.4- to 3.4-fold, compared with the control medium without carbon source, in medium containing an alternative carbon source, such as pyruvic acid and glyoxylic acid. The accumulated alpha(1)-antitrypsin in the medium containing pyruvic acid reached 18.2-24.2 mg/g-dry cell in 50-70 h by batch culture.

Evaluation of water and electrolyte transport of tubular epithelial cells under osmotic and hydraulic pressure for development of bioartificial tubules

Our aim was to develop bioartificial tubules using tubular epithelial cells and artificial membranes and evaluate the function of water and electrolyte transport by various tubular epithelial cells. The cells were cultivated onto extracellular matrix (ProNectin F) coating polycarbonate membrane. Water transport from the apical to the basolateral site of cells was examined using a modified Ussing chamber module. Water transport under colloidal osmotic pressure on the apical site and hydraulic pressure on the basolateral site were higher in JTC-12, LLC-PK1 cells than in MDCK cells. Water transport under osmotic plus hydraulic pressure was highest in LLC-PK1 cells. We made bioartificial tubules using LLC-PK1 cells and polysulfone hollow fiber cartridges. Water and Na ion transport function was high, and BUN and creatinine passage was recognized in these bioartificial tubules. BUN and creatinine concentrations of reabsorption fluid in these bioartificial tubules were significantly lower than those concentrations of control media and of noncell attached polysulfone hollow fiber cartridges. Though LLC-PK1 cells were more preferable cells for the use of bioartificial tubules in terms of water and electrolyte transport, the passage of BUN and creatinine was not appropriate for clinical use. To select more preferable cells for bioartificial tubules which transport water and electrolytes and do not induce passage of uremic toxins is necessary.

Vascular tumor in the mediastinum

Mediastinal venous hemangioma is a very rare neoplasm. Here, we describe our experience in treating a patient demonstrating such a tumor. The patient, a 23-year-old man, was admitted to our hospital because of a mediastinal cyst. A biopsy of the cystic wall was performed by Video-Assisted-Thoracic-Surgery, in April 1999. Clear serous fluid was found in the cyst, and it was thus incorrectly diagnosed to be a thymic cyst. The cyst continued to increase in size, and the patient began to show an increased temperature after being discharged. A resection of the tumor was performed in June 1999. The cyst was filled with bloody fluid and, according to the pathological analysis, was diagnosed to be a mediastinal venous hemangioma.

Electrophysiologic analysis of antidepressant drug effects on the GABA(A) receptor complex based upon antagonist-induced encephalographic power spectrum changes

To better understand antidepressant drug effects on the GABA(A) receptor complex (the GABA(A) receptor, chloride ionophore and benzodiazepine receptor), we investigated how antidepressants influenced power spectrum changes induced by pentylenetetrazol (PTZ), a chloride ionophore antagonist, in the rat hippocampal electroencephalogram (EEG). In control recording, PTZ (27.5 mg/kg i. p.) increased EEG power at frequencies under 12 Hz up to five times. After rats were pretreated with imipramine, fluoxetine or trazodone for 7 days (10 mg/kg i.p., twice a day), PTZ could not increase EEG power to more than three times the power before injection; this effect was not observed after pretreatment for 3 days. These three antidepressants inhibit serotonin uptake, while two other antidepressants, desipramine and nortriptyline, that inhibit norepinephrine uptake failed to counter the PTZ effect. We concluded that antidepressants with serotonergic effects enhanced the function of the GABA(A) receptor complex.

Expression and purification of functional human alpha-1-Antitrypsin from cultured plant cells

Human alpha-1-antitrypsin (AAT), the most abundant protease inhibitor found in the blood, was expressed in rice embryonic tissue suspension cell culture. This was accomplished by cloning the codon-optimized AAT gene into a vector containing the rice RAmy3D promoter and its signal sequence. The synthetic gene incorporates codons synonymous with those found in highly expressed rice genes. Approximately 1000 stable transformed calli were produced by particle bombardment mediated transformation and were screened for high AAT expression using a porcine elastase inhibitory activity assay. The band shift assay also confirmed that rice-derived AAT is functional regarding its binding capability to the elastase substrate. Time course studies were conducted to determine the optimum, postinduction expression levels from cell culture. AAT expression equivalent to 20% of the total secreted proteins was achieved, and a purification scheme was developed that yielded active AAT with purity greater than 95%. The potential applications of purified plant-derived AAT for treatments of various AAT-deficient diseases are discussed.

Cystatin C and cathepsin B in CSF from patients with inflammatory neurologic diseases

BACKGROUND

In CSF, proteolytic enzymes are believed to have crucial roles in the initiation and progression of inflammatory neurologic diseases (IND). Cystatin C, a major cysteine protease inhibitor in CSF, is tightly bound to cathepsin B and H.

OBJECTIVE

To determine if cystatin C is involved in the disease process of IND, the authors measured the cystatin C concentration by ELISA method and cathepsin B and H activities in the CSF of patients with acute IND.

METHODS

Cystatin C concentration and cathepsin B and H activities were measured in CSF samples taken from patients during the acute phase of their disease. Subjects studied were 8 patients with Guillain-Barré syndrome (GBS), 5 with chronic inflammatory demyelinating polyneuropathy (CIDP), 12 with MS, 16 with aseptic meningitis, 15 with neurodegenerative diseases as disease controls, and 35 healthy controls.

RESULTS

A significant decrease in CSF cystatin C level was seen in the patients with GBS, CIDP, and MS compared to the control subjects. High cathepsin B activity, but not cathepsin H activity, was also observed in the patients with GBS, CIDP, and MS.

CONCLUSION

Cystatin C levels in CSF measured by ELISA may help the physician recognize GBS, CIDP, and MS. Decreased levels of cystatin C may be related to the high levels of cathepsin B activity seen in the CSF of patients with GBS, CIDP, and MS.

Toremifene-induced fatty liver and NASH in breast cancer patients with breast-conservation treatment

We have described fatty liver, diagnosed by computed tomography scanning (CT) in more than 30% of patients with breast cancer who received tamoxifen. Therefore, it is urgent to elucidate the frequency and the degree of fatty liver induced by toremifene, an analogue of tamoxifen, which is also used in breast cancer. We enrolled 52 breast cancer patients who were treated with breast-conservation treatment and administered oral toremifene for 3-5 years as adjuvant endocrine therapy. We evaluated the degree of fatty liver by abdominal CT performed annually. CT demonstrated toremifene-induced fatty liver in four (7.7%) of 52 breast cancer patients. Toremifene-induced fatty liver did not correlate with abnormal levels of AST, ALT, GGT or total cholesterol. One patient who demonstrated moderate fatty liver by CT was histologically diagnosed as non-alcoholic steatohepatitis (NASH) by liver biopsy. The incidence of toremifene-induced fatty liver was significantly lower than that induced by tamoxifen. Accordingly, in terms of fatty liver and NASH, toremifene is considered to be more appropriate agent than tamoxifen. Though toremifene is less likely to induce fatty liver, the possibility remains that toremifene-induced steatohepatitis occurs. Because the diagnosis of fatty liver or NASH can be easily missed if only a blood test is performed, it is necessary to screen fatty liver by annual CT examination for patients who receive an antiestrogen agent.

Effects of sugar concentration on recombinant human alpha(1)-antitrypsin production by genetically engineered rice cell

Productivity of recombinant human alpha(1)-antitrypsin (rAAT) with a genetically engineered rice cell using an inducible promoter has been studied by batch-wise and continuous production. A simple model explained the effect of proteases released from the disrupted cells on the rAAT degradation. Glucose concentration in the medium significantly affected the rAAT productivity in the continuous production, because the rAAT was induced by sugar depletion. When the fresh medium containing 5mM glucose was supplied to the continuous bioreactor, induction time was long and the productivity was low, indicating that the glucose concentration in the cells was high enough as to repress the promoter. When the glucose concentration in the fresh medium was reduced to 0.5mM, total amount of rAAT produced in 70h cultivation reached 6.7-7.6mg/g-dry cell, which was two times larger than the control medium without glucose.